Cucurbita maxima x Cucurbita moschata rootstock are used to prevent infection with Fusarium oxysporum f. sp. niveum in watermelon production; however, this rootstock is not effective against nematode attack. Because of their vigor, the grafted plants can be planted at lower plant densities than the non-grafted plants. The tolerance to Fusarium oxysporum f. sp. niveum and Meloidogyne incognita was assessed in watermelon plants grafted onto a hybrid of Citrullus lanatus cv Robusta or the Cucurbita maxima x Cucurbita moschata cv Super Shintoza rootstocks. The densities of plants were 2083 and 4166 plants ha -1 . Non-grafted watermelons were the controls. The Crunchy Red and Sangría watermelon cultivars were used as the scions, it the latter as a pollinator. The experiments were performed for two production cycles in soils infested with Fusarium oxysporum f. sp. niveum and Meloidogyne incognita. The incidence of Fusarium oxysporum f. sp. niveum was significantly greater in the non-grafted than in the grafted plants.The grafted plants presented similar resistance to Fusarium regardless of the rootstock. The root-knot galling index for Meloidogyne incognita was significantly lower in plants grafted onto Citrullus lanatus cv Robusta than onto the other rootstock. The yields of plants grafted onto Citrullus lanatus cv Robusta grown at both plant densities were significantly higher than in the other treatments.Index terms: Citrullus lanatus; grafting; triploid; Fusarium oxysporum; root-knot nematodes. RESUMOA enxertia de Cucurbita maxima x Cucurbita moschata tem sido usada para prevenir problemas com Fusarium oxysporum f. sp. niveum na produção de melancia embora não seja efetivo contra ataque de nematóides. Em razão de seu vigor, plantas enxertadas podem ser plantadas em densidade mais baixa do que as plantas não enxertadas. A tolerância a Fusarium oxysporum f. sp. niveum e Meloidogyne incognita foi avaliada em plantas de melancia enxertadas em híbridos de Citrullus lanatus cv Robusta e em Cucurbita maxima x Cucurbita moschata cv Super Shintoza. Foram usadas densidades de plantas de 2.083 e 4.166 plantas ha -1 . Como testemunhas usou-se plantas não enxertadas. Os cultivares de melancia Crocantes vermelhas e Sangria foram usados como polinizador. O experimento foi realizado em dois ciclos, sendo instalado em solo infestado com Fusarium oxysporum f. sp. niveum e Meloidogyne incognita. A incidência de Fusarium oxysporum f. sp. niveum foi, significativamente, maior em plantas não enxertadas. Plantas enxertadas apresentaram resistência semelhante ao Fusarium independentemente do porta-enxerto. O índice de galhas de Meloidogyne incognita foi significativamente menor em plantas enxertadas em Citrullus lanatus cv Robusta. As maiores diferenças significativas em relação aos demais tratamentos foram observadas em ambas as densidades de plantas enxertadas pela produtividade das plantas enxertadas em Citrullus lanatus cv Robusta.Termos para indexação: Citrullus lanatus; enxertia; triplóides; Fusarium oxysporum; nematóides d...

En México, ha sido un reto satisfacer la demanda nacional de arroz que superan las 850 000 toneladas anuales, por lo que en los últimos años se ha recurrido a la importación. Ante ello, a fin de contrarrestar esta situación, se ha incentivado el desarrollo de tecnologías propias a los sistemas de producción y la implementación de programas de mejoramiento genético orientados a la generación de genotipos y su adaptación a las zonas arroceras del país. A pesar de los esfuerzos, aun se carece de variedades de arroz de grano largo y delgado que son de buena calidad industrial del grano y competitivo con los arroces de importación; además, que son preferidos por el consumidor. En consecuencia, en la región arrocera de Michoacán se identificaron líneas de arroz avanzadas, donde surgió el genotipo Lombardía FLAR 13. Durante los ciclos 2017 a 2020 este material fue evaluado experimentalmente en comparación con el genotipo Milagro Filipino en Lombardía, municipio de Gabriel Zamora, Michoacán. Se registraron variables morfológicas y productivas. Con los datos obtenidos además de la verificación de las pruebas de normalidad y homogeneidad de varianzas, se analizaron con la prueba estadística t-student para muestras independientes. Los resultados mostraron superioridad del genotipo Lombardía FLAR 13 sobre el genotipo Milagro Filipino, ya que en la mayoría de las variables morfológicas evaluadas igualó, e incluso superó en las variables productivas, particularmente en esta última, los rendimientos fueron superiores a 9 t ha-1, además presentó estabilidad productiva durante los ciclos evaluados, por lo que es competitivo con la variedad convencional Milagro Filipino que se establece en la zona.

Para conocer la incidencia de plagas en injertos de jitomate sobre parientes silvestres, muestreos semanales del 17 de Noviembre de 2007 al 16 de Febrero de 2008 fueron implementados en Ciudad Morelos, Municipio de Paracuaro, Michoacán, México. Se conformaron 13 tratamientos: seis ecotipos silvestres de Solanum lycopersicum var. cerasiforme (“tinguaraque”), seis injertos de jitomate cv Toro®  en tinguaraque y un testigo (cv Toro®). Las principales especies de insectos registradas fueron Bemisia tabaci, Bactericera cockerelli y Aphis gossypii. Los tinguaraques de fruto pequeño (1,05-1,22 x 1,10-1,25 cm de diámetro polar y ecuatorial) mostraron menor incidencia de insectos que los tinguaraques de fruto grande (2,12-2,23 cm de diámetro polar x 2,41-2,55 cm de diámetro ecuatorial) y el jitomate cv Toro. La resistencia a plagas también se manifestó en los injertos, en donde la incidencia de insectos fue desde 1,7 hasta tres veces menor que en jitomate; así, el injerto Grande Apatzingán (GAp) fue resistente a B. tabaci (5.87 ± 4.61), adultos de B. cockerelli (1,37 ± 1,18) y A. gossypii (1,5 ± 1,2). En jitomate, la incidencia de esos insectos fue de 9,74 ± 8,52, 2,26 ± 1,99 y 4,8 ± 5,2, respectivamente. Los resultados sugieren que la técnica de injerto sobre parientes silvestres tiene potencial en programas de manejo integrado de plagas del jitomate.

Grafting Carica papaya plants can have several benefits for productive, phytosanitary, and sexing purposes. However, the literature on the subject of papaya grafting is limited. The tongue approach and cleft grafting techniques seem to be the most adequate for C. papaya, but the quality of grafts depends on several factors. With the objective of developing and adapting a grafting method for papaya, experimental assays were carried out in the Valley of Apatzingan, Michoacan, Mexico. The physical condition of the seedlings was assessed, and the most advantageous time for grafting was determined based on the size and thickness of the stems. Three assays were then carried out. The first assay was a test of the tongue approach and cleft grafting techniques using two clamping devices. The second assay involved the same techniques with modifications and the addition of another treatment. In the third assay, the modified tongue approach grafting method was tested on three containers with papaya plants. Seedling vigor, graft survival, and graft quality were the recorded variables. The results indicated that unwanted tissue should be cut 6 days after grafting. The tongue approach grafting method using tape as the fastening device (T-T) yielded a graft survival of 80%. The modified tongue approach grafting method, in which the tongues were formed just below the stem-site cut and tape was used as the fastening device (M-T-Bc-T), yielded a graft survival of 90%. In the third assay, the previously described modified method, but with seedlings grown in plastic bags (M-T-Bc-T-B), yielded a graft survival of 92.5%. It can be concluded that the modified tongue approach grafting method with seedlings grown in plastic bags (M-T-Bc-T-B), is a reliable grafting method for papaya that does not require special handling conditions.

In Mexico, the national demand for rice exceeds four times the consumption of the grain produced internally, which has caused growing volumes of imported rice. Long and thintype rice is the one with the highest consumption. Faced with this problem, a strategy was implemented based on the evaluation, validation, and release of rice materials. Since Michoacán State is involved in rice production, evaluations have allowed the selection of materials, which has resulted in the current availability of a number of advanced experimental lines. Also, the technology that has traditionally been used in the cultivation had changed, so that continuous improvement programs have been developed represented by the system of cultivation in direct sowing in furrows and continuous irrigation. The new varieties do not require continuous flooding, which allows for a greater efficiency in the use of water and soil resources. Studies on rice nutrition in Mexico are still scarce, especially under irrigated conditions. The current has focused on the nitrogen fertilization of this crop since the exploration of the efficient management of soil nutrition is a vitally important issue. Other aspects integrated to the rice technology are the use of a low seed rate and weed management using a new generation of herbicides.